Ion implanation of titanium workpieces without surface discoloration
US4693760A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 12, 1986 |
| Grant date | Sep 15, 1987 |
| Priority date | — |
| Expiry date | May 12, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/90
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A process for preventing surface discoloration in orthopedic implants made of titanium and its alloys is disclosed. Such surface discoloration is apt to occur when the orthopedic implants are ion implanted to improve their wear characteristics. The process essentially includes exposing all fixtures and shields, made of pure titanium, located in an implant chamber, to an ion beam, creating a vacuum within the chamber not exceeding about 5.times.10.sup.-5 torr, introducing an orthopedic implant within the chamber to be directly exposed to the beam, and reducing the ion beam current power density so as not to exceed about 1.0 watt/cm.sup.2. Exposing the fixtures and shields to the ion beam first serves to remove surface contamination therefrom, followed by forming a surface layer thereon. This surface layer effectively lowers the sputtering coefficient of the fixtures and shields, and thus reduces the amount of material sputtered from areas exposed to the ion beam to unexposed areas. Preferably, the vacuum is created by using an oil-free vacuum pump.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.